In general, flat panel display devices such as a PDP, an LCD, etc., are equipped with an anti-reflective film so as to minimize reflection of incident light from the outside.
Methods for minimizing the reflection of light include a method of dispersing a filler such as inorganic fine particles, etc. in a resin, coating it on a substrate film, and imparting unevenness (anti-glare: AG coating) thereto, a method of using light interference by forming multiple layers having different refractive indexes on a substrate film (anti-reflective; AR coating), a method of using them together, etc.
Among them, in the case of the AG coating, although the absolute amount of reflected light is equivalent to common hard coatings, a low reflection effect can be obtained by reducing the amount of light entering the eyes using light scattering through unevenness. However, since the AG coating lowers screen sharpness due to the surface unevenness, recently, many studies on the AR coating are progressing.
As a film using the AR coating, those having a multi-layered structure in which a hard coating layer (high refractive index layer), a low reflective coating layer, etc. are stacked on a substrate film are being commercialized. However, since the method of forming multiple layers separately conducts the processes of forming each layer, it has a disadvantage in terms of lowered scratch resistance due to weak interlayer adhesion (interface adhesion).
Previously, in order to improve scratch resistance of the low refractive layer included in the anti-reflective film, a method of adding various particles of a nanometer size (for example, silica, alumina, zeolite, etc.) was mainly attempted. However, when using nanometer-sized particles, it was difficult to simultaneously increase scratch resistance while lowering the reflectance of the low refractive layer, and due to the nanometer-sized particles, the anti-pollution property of the surface of the low refractive layer was significantly deteriorated.
Accordingly, in order to reduce the absolute reflection amount of incident light from the outside and improve the anti-pollution property as well as scratch resistance of the surface, many studies are being progressed, but the resulting property improvement degree is unsatisfactory.